Interconnecting multiple blood bags are sold for the collection of blood under sterile conditions and then for the processing of the various blood components through centrifugation, followed by expulsion of the components such as blood plasma from the original bag, in which the blood is collected, to a transfer bag through connecting tubing.
Generally, a valve means is used to close the tubing between the two bags until the transfer operation is to take place. Thereafter it is once again desirable to close the communication by means of a valve.
In U.S. Pat. No. 3,685,795 a cannula valve is disclosed comprising a spike for puncturing a diaphragm to open the flow path, and also providing other valving means for reclosing the path again as desired. However, this structure must be collapsed to rupture the diaphragm, and then must be reextended again to open the flow path. Also, the components of the device are rather expensive and difficult to assemble. Likewise, upon withdrawal of the spike from the membrane area, the flap of the punctured membrane may swing out into transverse relation to the tubing, again blocking flow through the tubing and the valve.
U.S. Pat. No. 3,110,308 discloses a hollow cannula which is separate from and free-floating in the bore of tubing, passing between a pair of sterile medical fluid containers. This free-floating cannula can be manipulated forwardly from the outside to puncture a diaphragm. However, the structure provides no capability for resealing of that device.
The structure of this invention exhibits a novel valve system utilizing a membrane for initial sealing and a cannula for initial opening, and providing a resealing capability, plus means for prevention of the ruptured membrane swinging back to obstruct the flow path through the tubing in which it resides.
The device of this invention provides an open valve immediately after penetration of the diaphragm, without withdrawing, while still permitting resealing of the valve.